Endoluminal surgical tool with small bend radius steering section

ABSTRACT

An endoluminal surgical instrument has first and second steering controls on a handle. A flexible shaft attached to the handle has a distal steerable end including a first link and a second link separated by a plurality of intermediate links. First and second steering elements, such as pairs of steering wires, are linked to first and second steering controls and to the first and second links. One or more of the links is pivotable through an angle of at least 30 degrees relative to an adjoining link. The set back position of the second steering elements from the first steering elements, and the pivoting capability of the links allows the steerable end to be steered into a small bend radius. This makes the instrument highly maneuverable for use in endoluminal surgery, such as incision-less surgery of the stomach.

PRIORITY CLAIM

This Application is a Continuation of U.S. patent application Ser. No.13/483,371, filed May 30, 2012, now pending, which is aContinuation-in-Part of U.S. patent application Ser. No. 12/061,591,filed Apr. 2, 2008, now pending. These applications are incorporatedherein by reference.

BACKGROUND

Various endoscopic systems have been successfully used to perform a widevariety of diagnostic and surgical procedures. Most of these types ofsystems having a steering capability. Specifically, the leading ordistal end of the endoscopic surgical instrument can be introduced intothe body, for example into the stomach via the throat, with thephysician then steering the tip of instrument. The steering is typicallyachieved via four steering wires attached to wheels, levers, or otheractuators on the handle of the instrument, which remains outside of thebody. By manipulating the actuators, the physician can steer the tip ofthe instrument in the up/down and left/right directions. This allows thephysician to position surgical tools as desired.

In order to provide the most steering flexibility, the distal end of theinstrument advantageously can bend into a tight radius, via control ofthe actuators on the handle. However, the bending radius is limited bycertain factors. One factor is that the pivoting links that make up theskeleton or frame of the instrument can only pivot to limited anglerelative to each other. Another factor is that the left/right andup/down steering movements are not entirely independent. Specifically,when the distal end of the instrument is steering to it maximum left orright steering position, the ability to also steer in the up or downdirection becomes very limited, and vice versa. As a result, operatingthe instrument to position the instrument tip as desired can becomedifficult.

Accordingly, engineering challenges remain in designing endosurgicalsystems allow for highly flexible positioning options.

SUMMARY

In a first aspect, an endoluminal surgical instrument has first andsecond steering controls on a handle. A flexible shaft attached to thehandle has a distal steerable end including a first link and a secondlink separated by a plurality of intermediate links. First and secondsteering elements, such as pairs of steering wires, are linked to firstand second steering controls and to the first and second links. One ormore of the links is pivotable through an angle of at least 30 degreesrelative to an adjoining link. The set back position of the secondsteering elements and the pivoting capability of the links allows thesteerable end to be steered into a small bend radius. This makes theinstrument highly maneuverable for use in endoluminal surgery, such asincision-less surgery of the stomach.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a back, top, and right side perspective view of an endoscopicsystem.

FIG. 2 is a front, top, and left side perspective view of the shapelockassembly shown in FIG. 1.

FIG. 3 is a schematically illustrated side view of the distal end of theendoscopic system shown in FIG. 1.

FIG. 4 is an enlarged schematically illustrated side view of the tip ofthe instrument shown in FIG. 3.

FIG. 5 is a schematically illustrated section views taken along line 5-5of FIG. 3.

FIGS. 6 and 7 are cross-sectional views of the endoscopic system ofFIGS. 1-5.

FIG. 8 is a side view of the distal end of a tight bend radiusinstrument, with the sheath or outer covering removed for purpose ofillustration.

FIG. 9 is a side view of the instrument shown in FIG. 8 steered into anear maximum up position.

DETAILED DESCRIPTION OF THE DRAWINGS

Turning to the drawings, as shown in FIGS. 1 and 2, an endoscopic system30 includes a reusable shapelock assembly 34 that is adapted for usewithin a disposable assembly generally designated 32. The disposableassembly 32 has a flexible sheath 38 attached to a relatively rigidhandle 36.

The sheath 38 includes a tip 58 attached to the distal end of asteerable section 42. A body section 40 of the sheath 38 extendsproximally from the steerable section 42 to the handle 36. A lock nut orsimilar attachment holds the proximal end of the body section 40 of thesheath 38 onto the handle 36.

Referring to FIGS. 3 and 4, the sheath tip 58 has one or more tool lumenopenings 60. A plurality of tool lumens extend through the interior ofthe sheath 38. The tool lumens are defined by one or more structuralguideway members provided within the interior of the sheath 38. In theembodiments shown, the tool lumens are defined by a plurality of sleevesor tubes 44 and 46, each having an open distal end that is sealed arounda respective lumen opening 60 in the tip 58. The tubes 44 and 46 extendback from the tip 58 through the length of the sheath 38 to the handle36. The tubes may be flexible rubber or plastic tubes that act asguideways between the handle 36 and the tip 58 for tools andinstruments. The tubes may alternatively be flexible tubes having acomposite construction, such as a multi-layer extrusion, or coil and/orbraid reinforced construction. The tubes may be constructed to reduce oreliminate the likelihood that the tubes will become twisted, kinked,tangled, torn, or to prevent the lumens of the tubes from collapsingunder vacuum.

Referring still to FIGS. 3 and 4, the steerable section 42 at the distalend of the sheath 38 may be formed by segments, links, or othergenerally rigid and pivotably interconnected elements. In the exampleshown, the steerable section 42 includes links, with the first linkshown at 74 and the second link at 76. The length and flexibility of thesteerable section 42 is varied by selecting the number and size of theindividual links making up the steerable section 42.

As shown in FIG. 8, a first pair of steering wires 80A or other steeringelements are attached onto opposite sides of the first link 74 atattachment points 83. Generally the first link 74 is the front orleading link which the tip 58 attached to.

A second pair of steering wires 80B are attached to opposite sides of asecond or proximal link 75 at attachment points 81. The proximal link 75is spaced 4-30, 8-24 or 12-20 cm behind the first link 74, with severalintervening links 77 between the first link 74 and the proximal link,for steering the steerable section 42. The steering wires 80A and 80Bextend back from the first link 74 and the proximal link 75 andsubsequent proximal links of the steering section 42, through the sheath38 to the handle 36.

Alternatively, the subsequent proximal links, i.e., links between thehandle and the proximal link 75 may be omitted and replaced with atubular structure not having any links. The links are pivotally attachedto each, with alternating angular positions, i.e., with even linkspivotable in the up/down direction and with odd links pivotable in theleft/right direction. The links are designed to allow at least 30, 35,40, 45, or more degrees of pivot movement or angular rotation betweenadjoining links. The attachment of the second steering wires 80B ontothe proximal link spaced behind the first link 74, and the pivotingcapability of the links, allows the steerable end to be steered into asmall bend radius. This makes the instrument highly maneuverable for usein endoluminal surgery.

The steering wires may be provided within coils 82 or other columnstrength element. The coils 82, if used, allow the steering wires to betensioned without buckling the sheath 38. The steering section may beabout 4-10 cm long, whereas the sheath 38 is typically between 20-200cm.

Referring to FIGS. 4 and 5, the sheath 38 has an outer skin or layer 206formed of a material such as a polymeric or plastic material that isflexible and that provides a protective layer to prevent passage ingressof bodily fluids. The cylindrical proximal end 72 of the tip 58 issealed onto the outer skin 206 via an adhesive or other bonding orattachment method. The tip 58 may be removably attached to the distalend of the sheath 38, such as by screwing, friction fit, or othermechanism adapted to provide the user with the ability to exchange tipsfor various procedures. The tip 58 may be made of hard or soft plasticor rubber, or similar non-porous materials. As the sleeves or tubes 44,46 are sealed at the lumen openings 60 of the tip 58, gases and liquidsencountered during use of the system 30 within the body aresubstantially prevented from entering into the sheath 38, except throughthe tubes.

As shown in FIG. 5, passageways 212 for the steering wires may beprovided within the walls of the sheath 38. Each passageway 212 may belocated within the skin material, between first and second layers ofbraid or reinforcement material. The passageways 212 may be formed instraight or spiral, radially spaced alignment extending over the lengthof the sheath 38.

FIG. 2 shows a locking handle 172 that opens at its distal end. Theshape lock body 150 is formed by segments, such as links that arepivotably attached to (or positioned next to) each other in a nestedarrangement. The links may be formed as nested rings, so that theshapelock body 150 is tubular, or has an open internal throughpassageway.

Referring to FIG. 3, at position 180, the steering wires 80A exit fromthe passageways 212, run inside of the steerable section 42, and attachto the first link 74 of the steerable section 42. The other pair ofsteering wires 80B attach to the proximal link 75 spaced proximallyapart from the first link.

Toward the proximal end of the sheath 38, the steering wires arecontained within the passageways 212 and extend to the handle 36, wherethe steering wires 80 are operably connected to the control knobs 140and 144.

Consequently, the shape lock 34 may be inserted into the central sheathopening 220 without contacting or interfering with the steering wires.

Turning to FIGS. 6 and 7, cross-section views of the endoscopic system32 shown in FIG. 1. The sheath 38 may have a composite construction,including an outer layer 322, a body member 324, and an inner layer 326.The composite construction provides the shaft with improved strength,flexibility, and torque transmission capability over conventionalendoscopic shaft constructions. The outer layer 322 and inner layer 326may each include one, two, three, or more layers of a braided or wovenmesh reinforcement material, such as polyethylene terephthalate (PET),nylon, metal or metallic fibers, or other suitable reinforcementmaterial. The braided or woven mesh reinforcement layers are preferablyporous, thereby providing the ability for a bonding material topenetrate the reinforcement layers.

FIGS. 6 and 7 also show the tubes 44 and 46, as well as two additionaltubes 48 and 50, which may optionally also be included within the sheath38. If used, the tubes 44 and 46 may be larger diameter tubes having anID of about 3 mm to about 9 mm, preferably about 6.3 mm, with tubes 48and 50 having a smaller diameter tubes, with an ID of about 1.5 mm toabout 7 mm, preferably about 4 mm.

The outer diameter of the sheath 38 may preferably be in the range ofabout 10 mm to about 30 mm. The steering wires 80 extend from thesteering controls 140 and 144 on the handle 36 through the sheath 38 tothe distal end of the shaft at links 74 and 75. The steering wire coils82, if used, receive and retain the steering wires 80. The steering wirecoils 82 may be formed integrally with or embedded in the sheathstructure. Alternatively, the steering wire coils 82, along with thetubes 44-50, may float within the inner lumen 220.

Thus, novel methods and apparatus have been shown and described. Variouschanges and substitutions may of course be made without departing fromthe spirit and scope of the invention. The invention, therefore, shouldnot be limited except by the following claims, and their equivalents.

1. An endoluminal surgical instrument, comprising: a handle; first andsecond steering controls on the handle; a flexible shaft attached to thehandle; the flexible shaft having a distal steerable end including adistal link and a proximal link spaced proximally apart from the distallink by a plurality of intermediate links; and a first pair of steeringwires passing through the proximal link and attached to the distal link;and a second pair of steering wires attached to the proximal link, andwith all of the steering wires substantially equally radially spacedapart.
 2. The surgical instrument of claim 1 further comprising an endtip on a distal end of the flexible shaft and with a distal linkadjacent to the end tip.
 3. The surgical instrument of claim 2 with theend tip attached onto the distal link.
 4. The surgical instrument ofclaim 1 comprising 2-10 intermediate links.
 5. The surgical instrumentof claim 2 comprising two or more lumens extending from the handle tothe end tip.
 6. The surgical instrument of claim 1 with one or more ofthe links pivotal through an angle of at least 30 degrees relative to anadjoining pivotally attached link.
 7. An endoluminal surgicalinstrument, comprising: a handle; left/right and up/down steeringcontrols on the handle; a flexible shaft, with a proximal end of theflexible shaft attached to the handle; the flexible shaft having adistal steerable end including a distal link spaced apart from aproximal link by a plurality of intermediate links, with substantiallyeach intermediate link pivotal through an angle of at least 30 degreesrelative to an adjoining intermediate link; an end tip attached onto thedistal link; two or more lumens extending through the flexible shaftfrom the handle to the end tip; left and right steering wires extendingdistally from the left/right steering control to the proximal link, withthe left steering wire attached to a left side of the proximal link andwith the right steering wire attached to a right side of the proximallink; and up and down steering wires extending distally from the up/downsteering control, passing through or by the proximal link, andterminating at the distal link, with the up steering wire attached to atop of the distal link and with the down steering wire attached to abottom of the distal link, and with all of the steering wires equallyradially spaced apart.